“A long time ago, in a galaxy far, far away…” With this phrase begins one of the most important film sagas of all time. But there are no answers. How far? The truth is that when the movie script was written, the farthest galaxy found to date had nothing to do with the farthest nowadays. In fact, today the discovery of the most distant that has been detected so far is announced. It is neither more nor less than 13.5 billion light yearsso maybe the Galaxy of George Lucas’s films wasn’t that bad either.
This discovery has been announced just a few days after the finding of the most distant star to date was announced. this took place thanks to Hubble. In fact, it has been this space telescope that has found a good part of the most distant astronomical objects that have been detected. However, this new and distant galaxy has emerged from the collaboration between several telescopes: the Subaru, the VISTA, the UK Infrared and the Spitzer Space Telescope.
After 1,200 hours of observations, together they have detected HD1, an object that, to be honest, is actually a candidate for the most distant galaxy. It is to be confirmed. Observing its color, they calculated what its approximate distance could be, but they needed the help of the Atacama Large Millimeter/submillimeter Array (ALMA) to make follow-up observations that indicated it was 100 million light-years further away than GN-z11the galaxy that right now holds the record for the farthest.
What do we know about the farthest galaxy?
This candidate to be the most distant galaxy found so far is described today together with two studies, one published in Astrophysical Journal and another in Monthly Notices of the Royal Astronomical Society Letters.
It proposes two hypotheses about the origin and constitution of this object located at 13.5 billion light years. For one thing, it could be forming stars at a very intense rate. It could even be the point of origin of the stars of the Population III. Are are considered the first stars in the universe, born from the primordial material of the Big Bang, and so far it has not been observed where they formed.
On the other hand, scientists who have studied this outermost galaxy candidate believe it could contain a supermassive black hole approximately 100 million times the mass of our Sun.
But it is difficult to stay with one of the two hypotheses. The main author of the study, Fabio Pacucci, has explained in a Press release with a very simple simile the difficulty involved in the choice:
“Answering questions about the nature of such a distant source is like guessing the nationality of a ship from the flag it is flying, while far from land, with the ship in the midst of a gale and dense fog. One may be able to see some colors and shapes of the flag, but not all of it. Ultimately, it’s a long game of analysis and exclusion of implausible scenarios.”
Fabio Pacucci, astrophysicist.
And that’s what they’re doing so they can see through the mist and the gale. So far, they have seen that this candidate for the most distant galaxy is very bright in the range ultraviolet of the electromagnetic spectrum. This may give clues about the energetic processes that occurred within it billions of years ago. Let’s not forget that the light reaches us now, but that these stars were formed a long time ago and that some of them may even no longer exist.
Population III stars are known to be capable of producing more UV light than normal stars, so this would support the first hypothesis. However, a supermassive black hole would also be possible, because “as devours huge amounts of gashigh-energy photons can be emitted from the region around the black hole.”
And now that?
If the black hole option is confirmed, we would be facing another record, since it would be the first supermassive black hole known to humanity to be observed a lot. closer in time to the big bang compared to the current holder of said record.
The most distant galaxy and the closest supermassive black hole to the Big Bang. Let the Guinness of Records tremble. But you have to confirm it. As it is also necessary to ensure that the measured distance is correct. For all this, scientists have the current rock star of space telescopes: the james webb. You haven’t even finished setting up all your instruments yet and you already have a long to-do list.
We have to wait to find out if this is really the most distant and oldest galaxy that has ever been observed. If so, we would be on an astronomical landmark that occurred a long, long time ago, in an even more distant galaxy…